This invention relates to fluid dispensers, and in particular to a new and improved push-in type dispenser incorporating a one-way capsule valve for controlling flow between the container and the cylinder-plunger assembly. The dispenser is particularly suited for handling both viscus and nonviscus liquids. The presently preferred embodiment of the dispenser has been operated satisfactorily with free-flowing liquids and lotions having viscosities in excess of 5,000 cps.
Containers with horizontally oriented plungers for pump type dispensing of fluid from the container are known and have been used for some time. A typical conventional dispenser of this type has a cylinder with a plunger slidingly positioned therein, a first one-way valve for controlling flow from the container into the cylinder, and a second one-way valve for controlling flow from the cylinder through a flow path in the plunger to the exterior of the container. Dispensers of this type utilized an umbrella type valve as the first one-way valve and a flapper type valve as the second one-way valve. Containers with vertically oriented plungers also are known and have been used for some time. Dispensers of this type are disclosed and discussed in applicants copending application U.S. Ser. No. 07/232,679 filed Aug. 16, 1988 and reference may be had to that application for additional background information.
The umbrella valve is satisfactory in many situations. However such a valve is relatively expensive to produce, and problems have been encountered when the valve is used with high head pressures. Under such conditions valve operation is disturbed by the presence of foreign objects, such as dirt and hair, and very close control in the manufacturing process is required to produce consistently satisfactory umbrella valves.